Submarine signaling cable



Aug. 20,' 19355 J. J. GILBERT SUBMARINE SI GNALING CABLE Filed July 22, 1931 m ma J J I opposite to that of the twist of the cores.

Patented Aug. 20, 1935 UNITED STATES PATENT OFFICE SUBMARINE SIGNALING CABLE Application July 22, 1931, Serial No. 552,355 In Great Britain August 19, 1930 IClaim.

The present invention relates to submarine signaling cables, particularly to signaling cables of the twin-core or multi-core type. Hitherto twin-core and multi-core submarine cables have been constructed by twisting two or more insulated conductors together with jute wormings to form a cylindrical composite core over which Jute servings and armor wires are applied. Usually the armor wires are laid ina direction When such cables are submerged into great depths encountered in transoceanic signaling lines, the strain which is exerted during the laying of the cable causes the armor wires to straighten out; this results in a rotation of the cable in a direction which increases the twist of the cores. This increased twist results in considerable strain on the cores, causing either a deformation of the insulation or breakage of the central conductors.

, particularly at the joints thereof.

The present invention has for its object to avoid this dimculty. To this eifect the armor prises a twin-core submarine cable having the cores twisted together and embedded in insulating material having a substantially cylindrical exterior surface. A layer of jute may be applied over this insulating material and the'armor wires are applied externally over this Jute layer concentric with the axis of the cable and wound in the same direction as thecores are twisted. The layofthecoresmaybefromtltoifeetandthat ofthearmorwiresnotmorethan 2 feet.

Theinventionwillnowbedescribedwitb numerals 2 and I and the loading material by 5 4 and 5. The insulating material is indicated by numerals I and I. These cores are embeddedin extruded or otherwise applied insulating material I, which is covered by a layer of jute i.

It will be seen that the twin-cores 2 and I are arranged with a left to right twist and the lay thereof is of substantial length, approximately 3 or 4 feet for example.

The armor wires indicated by reference numeral it are, according to this invention, laid I in the same direction as that in which the cores are twisted. The lay or pitch of the wires is substantially shorter than that of the cores 1 and I and may be not more than 2 feet.

Itwillbeseenthatwhentensilestressesare will, under such conditions, be applied to the con- 35 ductors which are likely to cause fracture or distortion.

What is claimed is:

A deep sea communication cable comprising at least one pair of core conductors forming the out- 30 going path and the return path of a single circuit, said conductors being covered with insulat- 'ing material whereby they are electrically insulated from each other and from the surrounding medium when laid in water, said insulated 85 conductors being spiraled about each other with a definite pitch or length of lay, and a plurality of armor wires constituting the total armor wire protection of said cable laid spiralLy around the structure comprising said insulated conductors, 40

one another.

JOHN J. GILBERT. 

